Brake-shoe.



H. B. NICHOLS & e; M. RICHARDSON.

BRAKE SHOE.

APPLICATION IILED MAR. 27, 1914.

Patented Sept. 22, 1914.

2 SHEETS-SHEET 1.

H. B NICHOLS & G. M. RICHARDSON.

BRAKE SHOE.

APPLICATION FILED MAR. 27, 1914.

wvemtou Gum w,

2 SHEETS-SHEET 2.

n I I 1 I n I l I 1 I, I a w d 7 I e a 4 m l/lflld m l/I14 A W n Wibneooeo UNITED STATES PATENT OFFICE.

HENRY B. NICHOLS AND GEORGE M. RICHARDSON, or PHILADELPHIA, PnitNsYL- VANIA.

BRAKE-SHOE.

Specification of Letters fatentp Patented Sept, 22, 1914, Application filed March 27,1914.

Serial No. 827,671.

V the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements 1n Brake-Shoes,

of which the following is a specification,

reference being had therein to the accompanying drawing. 7 l

Our invention relates to railway equipment, automobiles, motor cars, wagons and other similar vehicles, and has for its object, the improvement of brake shoes in certain particulars which will be hereinafter set forth.

Heretofore, it has been common practice to make brake shoes of cast iron, which material in itself is subject to a number of objections. One of these is its granular tendency, and another its disposition to break across the middle, especially when partly worn through. On the other hand, steel shoes have been made of such a composition that the metal would have muchgreater intrinsic strength which would sufficiently resist the tendency to fracture, but ordinary steel, will not, under modern operatin conditions, develop as high a coefficient 0 friction as some special mixtures of iron. In both iron and steelshoes, the braking quality or frictional resistance has been im-- proved by the use of inserts, particularly such as are covered by United States Letters Patent to Stromeyer, Nos. 665,381, August. 7, 1900, 866,085, September 17th, 1907, and 966,616, August 9th, 1910.

Cast iron, which is the cheapest material, all. things considered, for this purpose, has heretofore been; chilled in order to increase its life by retarding the wear, and it has been proposed to strengthen it by different forms of inserts of tougher and more duetile metal. It is the aim of our present in vention to produce a composite shoe of this general type, which will be simple and cheap to manufacture, and at the same time will afford maximum wear with minimum breakage.

. \Ve attain our object by providing 'a lon-' gitudinal strip of ductile or Wrought iron or steel for the back of the shoe, combining therewith a separately formed lug of the same ductile or malleable iron or steel, and then casting the body so that the ductile parts will be partially embedded in the cast iron. In order to lengthen the life of the shoe, and. at the same time give greater braking power, we provide the body with cells in which a suitable composition is placed, as is above mentioned.

As will hereinafter more fully appeal, we introduce a number ofdetailed features of improvement, such as the use of spot welding to connect the malleable iron parts and the like. I

Our invention "is illustrated in the accompanying drawings in which' Figure 1 is a perspective View of a brake shoe constructed in accordance with our invention. "Fig. 2 is a similar perspective view of a form of stiffening strip or ductile back for the shoe. Fig. 3 is a perspective view of a ductile or malleable iron lug. Figs. 4, 5, 6 and 7 are all transverse sectional views of modified forms of 111g show ing different methods of securing the extremities of the lug to the backing strip;

Fig. 8 is a perspective view of a modified form of lug adapted to afford side bearing surfaces of the malleable iron without the interposition of cast iron asin Fig. 1; Fig. 9 is a longitudinal sectional view of the shoe shown in perspective in Fig: 1.- Fig. 10 is a time View of the shoe.

-Ref'err'ing to the drawings and particu larly to Figs. 1, 2 and 3, 1- i'ndicatesa backing strip or reinforce for the brake shoe; this strip being. made of ductile ormalle able iron or mild steel. As shown in Fig. 2', it is preferably provided at its ends with circular openings 2, and intermediate its ends with opposite recesses 3," intended to receive the ends of the lug 4. This lug 4 is made of the same malleable iron or mild steel as the strip 1, and is constructed in a peculiar way in order to secure maximum strength and resistance to distortion or breakage. It is composed of two members 4 and 4, both of which "are formed insubstantially U-shape, inverted, with the member 4 placed inslde of the member 4 and their flat closed portions or bases permanently and integrally joined by means ofspotwelding indicated by the circles at 4. This use of welding is a rather important feature of the present invention, as it entirely obviates a number of difiiculties which have heretofore arisen Wherever any member like this lug has been made in two parts secured together. Rivets work loose, and the junction produced by embedding the two parts together in a cast ing is not always secure and is very far from being stifl' enough for such purposes as ours. We find however that our duplex lug with the spotweld gives as good results in practice as a solid lug and with no liability to fracture.

To complete the simplest form of shoe such as that shown in Fig. 1, we assemble the parts of Figs. 2 and 3 by placing the inverted U-shape member 4 of the yoke in Fig. 3 astraddle of the strip 1, with the inturned lower ends of the yoke member turning in under the edges of the recesses 3. It should be observed that this combination can be made without the recesses, but in that case either the strip 1 must be much narrower, or the member 4 must of course be much wider, We prefer the proportions shown in Figs. 1 to 3, and for this specific arrangement provide the recesses. The parts 1 and 4 thus conjointly arranged are placed in the mold, and the body 5 of the shoe is cast in the form shown in Figs. 1', 9 and 10. In the matter of shape, the distinguishing characteristics of this form are first the upstanding extensions 5 and the end projections 6. The former are part of the cast iron, which in the pouring fills the spaces between the members 4 and 4" of the yoke, and by reason of the formation of the pattern, extend beyond the opposite edges of the yoke members, sloping obliquely from the bases 5 to the crowns 5, where they are flush with the edges of the yoke member 4. In practlce, this slope is not very sharp, the spread at the base being only 3;; 1nch, that is to say if the width of the yoke member 4 is 14; inches, then the width between thebase lines 5? would be 1% inches, giving a'projection of inch on each side. he purpose of this projection of the cast metal beyond the edges of the strap metal lug is to afford 'a better-fit and a perfect an g surface for the lu'g the'a cket The principal strain of course comes entirely on these faces in braking,'and while the lug 4 is strong enough, with its ends anchoredin the casting as shown, to resist longitudinal displacement from the shoe,-

our tests confirm the belief, that we have by this construction fully solved the problems stated in the preamble of this specification, and have fully attained our objects therein referred to. iron body which gives cheapness and braking etficiency, with an added efficiency by using the Stromeyer inserts. It has strength and decreased liability to fracture due to the insertion of the malleable iron or steel stiffening strip 1; it has ideal support and bearing surfaces by reason of the material and construction of the bridge or yoke 4, and the extensions 5 of the cast body; and finally it has extreme'rigidity and firmness in its assemblage by reason ofthe complete reinforced anchorage of all the malleable parts which are so embedded in the process of casting that the entire structure becomes an integral and indivisible unit.

Referring to Figs. 4 to 8 inclusive, we' have therein shown a number of modifica tions of the lug and of the method of securing the lug to the stiffening strip and the body of the shoe. In Fi 4 and 5, the

member 4 'is' shown with s orter arms than are integrally secured thereto by means ofs 0t welds 1. In assembling, the stiflening s rip and lug thus become a unifi'which issecured in the mold and anchoredinthe casting'thesam'e as before. E

In Fig. 6 we show anothermodi'fication, which t e stiffening stri each recess, and the lower ends of the member 4 instead of being bent inward are carried down and spot welded to the metal fla g l, as indicated at it This leav'eaa Our-shoe has a cast m V 7 1 still has; therecesses 3 in its opposite si es, but-the'metal isi turned down at 1 along the innerfedge of smooth-flush upper surface to the stiffening stri and affords a very secure anchorage in t e casting.

In Fig. 7 the construction is substantially the same as in Figgfi, except that the lower ends of the member 4 are welded directly to the edges of the stiffening strip 1, without any turned down flanges.

Fig. 8 shows in perspective, and with some exaggeration, a modified form of lug, having taper edges intended to take the place as bearing surfacesof the cast projections 5 in 1 and 9. The inner and outer members;

ona oth sides of the lug 4 are split from base to crown and spread apart so as to be onequarter inch wider at the base than at the crown. The ends of the member 4 may be formed in any of the shapes shown in the other figures, the distinguishing feature of this modification being the expanded taper of the ductile metal lug.

Having thus described our invention in terms of the best specific embodiments of which we are at present aware, we wish to state and to have clearly understood, that we are aware these embodiments can be modified in diverse particulars without departing from the spirit of the invention. We contemplate all such modifications as fall within the scope of the appended claims.

It is also to be clearly understood that we do not regard nor use the metal projections 5 as a reinforce, but only as a filler, and to furnish bearing surfaces in the holder.

We are aware that it has been heretofore proposed to use some form of malleable iron or steel lug which, being weak in itself, required a projection of the casting for reinforcing its grip and strengthening its holding of the key whichretains the lugv in the brake head. Our lug, by reason of its peculiar construction is amply strong and stiff. The projections 5 however furnish very good bearing surfaces, and serve very well as fillers.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A brake shoe comprising a cast body, a back made of ductile metal having fastening devices connected therewith, said back and the fastening devices being embedded in the body of casting, and the fastening devices being separated transversely of the body so as to leave spaces between them, and projections from the cast met-alassociated with said fastening devices filling said spaces and, furnishing'bearing faces to take the thrust due to braking.

2. A brake shoe comprising a cast body, a back made of ductile metal having one or more fastening devices connected therewith-,- said back and the fastening devices being embedded in the body of ca ng and be ng secured together independently 'of the cash mg meansof welded joints.

. brake shoe comprisin a back made of ductile metal of substan ially the full the otheriby means of, base welds, and an iron body cast upon and about said back and lug-,- so as to embed the, same in ,,the casting with the openings in the back filled and covered by the cast iron, and the members of the lug straddling. the recessed portion of the back.

4. A brake shoe comprising a cast metal body and a ductile or malleable metal lug for securing it in the brake head, said lug being made in inverted U-shape with inner and outer members welded together at their bases and with their ends separately em bedded in the cast body.

5. A brake shoe comprising a cast metal body and a ductile or malleable metal lug for securing it in the brake head, said lug being formed of two members secured together to form a double arch with united crown, and with its terminal members embedded in the casting of the body.

6. A brake shoe comprising a back made of ductile metal, a fastening device in the form of a double arch, one arch within the other, and a body cast upon the back and the ends of the fastening device so as tov embed the same within it.

7. A. brake shoe comprising a back made of ductile metal, a-- key lug made of two flat straps bent in U-shape, one within the other, with the ends straddling the back and the inner ends anchored thereunder, and a body cast upon the back so'as to embed the same and the ends of the lugwithin it.

8. A brake shoe having a malleable back with its ends anchored in the cast body, and akey lug formed of a double steel strap with one of its members within the other, both bent in U-shape, each with its ends anchored under the back of the shoe.

. 9. A brake shoe consisting of a back made of ductile metal, a fastening lug straddling the back and composed of aninner and an outer inverted U-shaped member, in combination with a cast metal body embedding the back and the ends of the lug members, with projections from the casting extending outwardly to fill the spaces between the inner and the outer members.

10. A brake shoe consisting of a back made of ductile'metal, a fastening lug straddling the back and composed of an inner and an outer inverted U-shaped member, in combination with a cast metal body emb ddi g the ba k and the ends of the 11 members, with' projections' from the casting ding the back and thereby being attached-to extending outwardly to fill the spaces bethe strap. tween the said members, and laterally to In testimony whereof We-aflix oursignaform bearing faces on opposite sides of the tures in presence of tWo witnesses.

5 lug. HENRY B. NICHOLS. r

11. A brake shoe comprisin a back made I of a ductile metal, an invei ced U-shaped GEORGE ON' strap straddling said back and having its \Vitnesses: ends Welded thereto, means for reinforcing H.- TIEFENBAGH,

10 said strap, and a cast metal body embed- L. R.LI1 MAN. 

